Machine-gun unit



May 31,1927.

,r. M. JERVEY MACHINE GUN UN`I-T Filed Jan.. 1s. 192s `2 Sheets-Sheet 1May-5311531521 A'l'. M. JERVEY MAHINE GUN UNH Fim Jan. 1s. 1926 2sheets-snaai l y 'N-lumai M degltg @ttm nui Patented May 31, 1927.

ai 2;. rags THOMAS lvr; Jammin, on 'ann Unrrnnsrarns ARMY, ABER-nnenPRVING- GROUND,

.MARYLAND Y MACHINE-GUN UNIT.'

Application. aiedfiaauary 1a, 19265 seriain'o. 815079.y

(snai-irannnnaarns ACT or rllhe inv-ention described hereinA may benscd. by the Government, or any of its oiiicers or employees inprosecutionor workrror the Government,or by any other person'in the'United' States, ,vithcaitv payment to Ime of` any royalty thereon, inaccordance with the act ot March 3, 1883; i

rlhis invention relates to, a machine gun unit and in 'particular ithas'reference to a sear release mechanism applicable for synchronizedguns mountedfon aircraft.

The principal object of this invention is to provide a sear releasemechanism for machine guns of the above specifiedl type 1n which a leveris utilized to release the scar, and this lever is so mounted as toloperate thesea-r more easily than, existing types yof releases while" atthe i same ytime supplementing the action of the'sear spring by normallytending to hold the sear'engaged, thereby increasing the positivelocking action of the sear and insuring semi-automatic operation of thegun. L

To these and other ends, my invention consists in the construction,arrangement, and combination oi' elements,'described hereinafter-'andpointed out inthe claims forming-a." part of this specification. n

A practical' embodiment ofmy invention is illustrated in theaccompanying drawings, wherein: Y n Y Fig. 1 is a transverse sectionalview through a machine gun showing, in rear'ele-y vation, a boltprovidedl with a searmechanism constructed in accordance with the i'n-vvention;

Fig; 2l is a sectional view through the bolt on. the line 2-2 of Fig l;v

Fig. 3 is a longitudinal sectional view through the bolt;

Fig. 4 is a view in front elevation of the assembled seal" and searrelease mechanism;

Figs. 5, 6, 7 and 8 are detail views of the lever;

Figs. 9, 10, 11 and 12 are detail views of the Sear;

Figs. 13 and 14 are ldetail views of the sear lever slide.

Referring to the drawings by numerals of reference:

There is shown at 5 the side plates of a machine gun between whichreciprocates the bolt G carrying the firing pin 7 which is cocked in awell `Known manner by the lever MARCH 3,1833; 22' saar.' L. 62751.).

8. The. pin isheld in cocked position byv a Sear 9V slid'able vertically-inlslots 6 cut' Iin Athe rear tace orthe bolt andi forced to ypin-Yengagint'g,position by,YV a, spring 10. i

The sejar is operate'dto release lthe tiring pin by meansv of atransversely swinging lever 11 whose connection 'with the sear 1s'preferably made by a slide 12 disposed in agroove 1'1 in the lever and'having a cylindrical projection or stud 12 receivable in'an apenture 9"inthe sear. The llever'S Substantially inthepform of; quadrant and inits normal? position ot restv ,whenfconnected to lthe sear it is-out of'equilibrium, its ulcruln 13 being' located at one side ofthe vbolt so asto liejabove andto'one side otthecentefr of .gravity of the leverandfthereby normally produce a force' acting -olithereturIlStiiokesupplementing the sea-rspring, for moving and holding the sear 1niringpinengalgement'.

of the lever or whenf the lever is at rest, and .Y Y

s In order that the movement of'the,lever may be transmitted to the searwith asllittle eitort as' possible, thefposition4 of the groove 11during' operation, is substantially along theV horizontal planeV so vasto,v reduce to` Ya minimumjthey resistance encountered in lifting' thesear and furthermore the slide works 'in the' outer-po'rtionofk thegrooveV to obtain a long lever arm. By thus converting1 circu 'it willYsupplement the ,action of the Sear spring in' preventing disengagementof the sear.

The lower circumferential portion of the lever is reduced as at 14 fordisposition in a slot or groove 15 in the bolt to prevent withdrawal ofthe lever after being assembled in the gun. A conventional trigger motorincludes the usual plunger 16 and a pa-wl 17 for rocking the lever andoperates in a well known manner to synchronize the action of the gun andthe airplane propeller. y

While in the foregoing there has been illustrated and described suchcombination and arrangement of elements, as constitute the preferredembodiment of my invention,

llarv intoV reciprocal motion. the force required Y to operate the searwill be 'considerably` less Y it is Ynevertheless desired to emphasizethe fact that intermetation ot the invention should only beconclusivewvhen made inthe lightol the subjoinedclaims.

I claim:

l. In a machinegun unit, a reciprocal breech bolt, aiiring pin carriedthereby and movable with respect thereto, a cooking lever for the pin, acentrally located scar, having an aperture, for holding the pin incocked position, a. lever ot substantially quadrant 'form tulcrumed atone side of the bolt so a's to place the leverin unstable equilibrium,

'said' lever formed with agroove positioned during operation of thelever "approximately 1n the horlzontal plane, and a slide .member disosed in the Orooveand havingY a. ro'ectv C h l in@r stud receivable inthe aperture of the sear.

2. Ina m chine gun unit. a reciprocal breech bolt,l a fringpin carriedthereby and movable with respect thereto, a cooking lever tor the pin, acentrally located sear, having an aperture, tor holding Vthe pin incocked position, af lever fulcrumed at one sidepof'the bolt and swingingacrossthefcenterv of the bolt, said lever formed witha groove posi-'tioned during operation of the lever approXimately in the horizontalplane, and a slide member disposedin the groove and having a vprojectingstud receivable in the aperture of the scar.

` 8. In a'I machine gun unit, a. reciprocal kbreech bolt, afirmg pmcarried thereby and vmovable With respect thereto, a cooking lever forthe pin, a centrally located Sear, having an aperture, Vfor holdingthepin in cocked position, a leverfulcrumed at one side' of thevcoimectiou' bretweenthe lever and thc scar whereby they move in unison.y

5.7111 a. machine gun unit, a reciprocal u Y breech bolt, a1 firing pincarried: thereby and mmovable With respect thereto, means 'tor cockl ingthe pin, a sliding seal' f'lior holding the pinin cocked position, ascar spring, a lever ulcrumedj on the bolt, and a connection between thelever andthe scar whereby they move in unison. Y

6. In aV machine gun unit, a reciprocal breech bolt, a firing pincarried thereby and movable with respect thereto, means for cocking thevpin, a, sliding scar 'tor-holding the pinin cocked position, a searspring VJfor moving the sear to engage the pin, and means svvingabletransversely of the bolt for disengagingthe sear, the normalposition otsa'id means being out of equilibrium so as to sup plement the actionofthe Sear spring.' f

7. In a machine Ygun unit, a reciprocal breechboln a firing pin carriedthereby and movable with respect thereto, means for cocking the pin, aAsliding sea'r for holding the pin in cocked positiom'a sear spring formoving the Sear to engage the pin, and means swingable transversely ofthe bolt for disen-l gaging the sear. f v

Y 8.'V In a machine gun,v a reciprocal breech bolt, a firing! pincarried thereby and movable With respect thereto, means for cockingthepin, a. sliding sear for holding'the pin'in cocked position, and searactuating means mounted on the bolt for swinging movement.

`9. In a machine gun, a reciprocal breech bort, a tiring pm carriedthereby and movable With respect thereto, means for cocking the Vpin,asliding sear for holding the pin in cocked positiomand swinging meansconnected tothe sear, the upward stroke olf said means disengaging thesear and the downward stroke moving the sear into firing pinengagement.V

10. The combination with a sear, of a lever fulcrumed adjacent the searand swingable across the path'ot travel of the scar, and a slidingconnection between the Vlever and scar. K l' Y THOMAS M. J ERVE Y.

